With the advent of digital video decoders being widely used in both consumer electronics and personal computers, these decoders must be fabricated in an inexpensive manner. Within predictive video decoders such as MPEG (Moving Pictures Experts Group) compliant decoders certain frames within the video sequence must be stored as reference frames since they are used to decode other frames within the video sequence. To store such reference frames, in MPEG terminology these frames are known as I and P frames, substantial amounts of memory are required to support the decoder functions. Presently MPEG decoders merely store an entire frame of decompressed pixelated video information as the reference images. These frames are subsequently used to decompress and predict other frames, e.g., so-called B frames, within the video sequence. Reducing the amount of memory required for storing such reference images would substantially reduce the overall cost of an MPEG decoder.
Therefore, a need exists in the art for a method and apparatus to efficiently accomplish reference frame storage.